Python中模拟enum枚举类型的5种方法分享

以下几种方法来模拟enum：（感觉方法一简单实用）

复制代码 代码如下:
# way1
class Directions:
up = 0
down = 1
left = 2
right =3

print Directions.down

# way2
dirUp, dirDown, dirLeft, dirRight = range(4)

print dirDown

# way3
import collections
dircoll=collections.namedtuple('directions', ('UP', 'DOWN', 'LEFT', 'RIGHT'))
directions=dircoll(0,1,2,3)

print directions.DOWN

# way4
def enum(args, start=0):
class Enum(object):
__slots__ = args.split()

def __init__(self):
for i, key in enumerate(Enum.__slots__, start):
setattr(self, key, i)

return Enum()

e_dir = enum('up down left right')

print e_dir.down

# way5
# some times we need use enum value as string
Directions = {'up':'up','down':'down','left':'left', 'right':'right'}

print Directions['down']